Low power wide area network communication mechanism

Abstract

The low power wide area network communication mechanism mainly allocates the semi-persistent scheduling (SPS) frames to the terminal devices having network access requirements sequentially by the gateway. The SPS cycle is composed of a plurality of SPS frames and at least one buffering frame. In each SPS cycle, a data reception window is activated by the gateway according to each allocated SPS frames; the SPS frames that the networked terminal devices belong to are activated synchronously within each SPS cycle in order for the networked terminal devices to perform a data transmission with the gateway during each SPS cycle and ensure that the data transmission does not overlap with the data sent by other terminal devices. The scheduling may be re-scheduled at a preset time interval to allocate the SPS frames of terminal devices that are inoperable or out of service area to the terminal devices having network access requirements.

What is claimed is: 
     
         1 . A low power wide area network (LPWAN) communication mechanism, comprises:
 a low power wide area network system architecture consisting of a gateway and at least one terminal device; each terminal device being preloaded with a network identification, the gateway periodically granting a semi-persistent scheduling (SPS) cycle comprising at least one SPS frame to provide service to the networked terminal devices;   wherein the LPWAN communication mechanism at least includes the following processes:
 a. granting network access applications, the gateway broadcasts a set of beacons comprising network ID and system frame information; when each terminal device receives the beacons broadcasted by the gateway, a network access request message must be sent to the gateway if a network ID that the terminal device belongs to matches with the network ID in the beacon; 
 b. allocating the SPS frames; when the gateway receives the network access request message sent from the terminal devices, a network access grant message is sent to the terminal devices that sent the network access request messages; and simultaneously the SPS frames within the system frame information are allocated sequentially to the terminal devices that send the network access request message; 
 c. setting a SPS frame activation time; when the terminal devices receive the network access grant message sent from the gateway, the terminal devices immediately start a timer according to the system frame information in order to make the SPS frames which the networked terminal devices belong to are able to be reactivated repeatedly in each SPS cycle; and 
 d. activating a SPS cycle service; in each SPS cycle, a data reception window is activated by the gateway according to each allocated SPS frames; the SPS frames that the networked terminal devices belong to are activated synchronously within each SPS cycle in order for the networked terminal devices to perform a data transmission with the gateway during each SPS cycle and ensure the data transmitted by other terminal devices does not overlap with each other. 
   
     
     
         2 . The LPWAN communication mechanism of  claim 1 , wherein the LPWAN communication mechanism sequentially repeats the step a to the step d at a preset time interval. 
     
     
         3 . The LPWAN communication mechanism of  claim 1 , wherein the SPS cycle is composed of a plurality of SPS frames and at least one buffering frame; when the gateway receives the data sent by the terminal device corresponding to each of the SPS frames, a feedback signal is sent to the corresponding terminal device synchronously; the any terminal device that has not received the feedback signal from the gateway is able to perform data transmission with the gateway via the next at least one buffering frame. 
     
     
         4 . The LPWAN communication mechanism of  claim 1 , wherein the LPWAN communication mechanism repeatedly re-executes the step a to the step d at a preset time interval; the SPS cycle is composed of a plurality of SPS frames and at least one buffering frame; when the gateway receives data sent by the terminal device corresponding to each of the SPS frame, a feedback signal is sent to the corresponding terminal device synchronously; the any terminal device that has not received the feedback signal from the gateway is able to perform data transmission to the gateway via the next at least one buffering frame. 
     
     
         5 . The LPWAN communication mechanism of  claim 1 , wherein the gateway via the SPS frames in the system frame information and in a manner of sending a network access grant message to the terminal devices that have sent network access request messages, the SPS frames in the system frame information are sequentially allocated to the terminal devices that have sent the network access request messages. 
     
     
         6 . The LPWAN communication mechanism of  claim 1 , wherein the terminal device first compares whether a network ID the terminal device belongs to and the network ID in the beacon are matched when each terminal device receives the beacon broadcasted by the gateway; if the network ID the terminal device belongs to matches with the network ID in the beacon, a network access request message is sent to the gateway. 
     
     
         7 . The LPWAN communication mechanism of  claim 1 , wherein the gateway via the SPS frames in the system frame information and in a manner of sending a network access grant message to the terminal devices that have sent network access request messages, the SPS frames in the system frame information are sequentially allocated to the terminal devices that have sent the network access request messages; and the terminal device first compares whether a network ID the terminal device belongs to and the network ID in the beacon are matched when each terminal device receives the beacon broadcasted by the gateway; if the network ID the terminal device belongs to matches with the network ID in the beacon, a network access request message is sent to the gateway.